The present invention-relates to a character input apparatus and a storage medium in which a character input program is stored. In particular, the present invention relates to a character input apparatus and a storage medium which realize a search function of smoothly and rapidly searching a character string consisting of at least one character, forming a sentence and having a meaning, from a character string dictionary, storing such character strings for searching.
The present invention relates to a structure in which, for example, in a portable terminal apparatus and a word processor having a pointing device such as a pressure-sensitive tablet instead of a keyboard, an ordinary input of sentences is performed for writing papers and E-mail by using the pointing device. Furthermore, the present invention relates to a structure and a program for allowing disabled people who have difficulty in inputting sentences by using a keyboard to input sentences in information equipment which requires an ordinary input of sentences for performing the above-mentioned operation.
Conventionally, as a sentence forming apparatus, a word processor 10 as shown in FIG. 23 is generally widespread. Such a word processor 10 has a keyboard 11 including a plurality of keys 11a which have such a size that people can easily operate by pressing them with their fingers, whereby input processing of sentences can be performed by using the keyboard 11. In FIG. 23, reference numerals 12 and 13 denote insert slots for floppy disks and a liquid crystal panel, respectively.
In recent years, a portable terminal apparatus such as an electronic organizer equipped with a sentence input function of the word processor as described above has been put to practical use. Representative examples of methods for performing input of sentences in such a portable terminal apparatus will be described below.
According to a first method, input of sentences is performed by using a keyboard which is much smaller than the keyboard 11 of the ordinary word processor 10 shown in FIG. 23 (e.g., which has a size of the palm of a hand).
According to a second method, a small keyboard is displayed on a display screen of the above-mentioned portable terminal apparatus, pressing of a displayed portion of a key on the display screen is detected by a pressure-sensitive sheet, and input processing of sentences is performed by using the displayed keyboard.
According to a third method, a handwriting detection portion utilizing a pressure-sensitive sheet is provided in the above-mentioned portable terminal apparatus, handwriting formed on the pressure-sensitive sheet is detected to recognize a pattern of characters, and input processing of sentences is performed by utilizing the recognition of such a character pattern.
However, the above-mentioned sentence input methods in the portable terminal apparatus have the following problems.
First, in the first method using a small keyboard, the keyboard is too small for people to manipulate the keys with their fingers, which makes it difficult to perform a key operation. Furthermore, it is required for those who are not familiar with a keyboard to look for a character on the top of each key for a key operation, and in inputting Japanese, after characters are input, they are required to be converted into appropriate kanji characters (i.e., Chinese characters), which results in a very bothersome input operation.
The second method in which a small keyboard is displayed on a display screen of a portable terminal apparatus also has the problems similar to those in the first method using a keyboard operation.
In the third method in which a pattern of input characters is recognized from handwriting by using a pressure-sensitive sheet, in the case where an unknown kanji character is input, it is required that the kanji character is once phonetically input by handwriting in the form of hiragana characters (i.e. , Japanese phonetic characters), and the hiragana characters are converted into a kanji character. Thus, input of kanji characters is not necessarily performed efficiently by pattern recognition. Furthermore, in the case where there is a problem of a recognition ratio of handwritten characters (i.e., in the case where a recognition ratio is small), handwriting input is required to be frequently re-done. In order to enhance a recognition ratio, it is required to contrive a structure for performing pattern recognition of handwritten characters, leading to an increase in cost.
It is needless to say that the above-mentioned first to third methods can make it difficult for visually impaired people to perform input operation of characters.
Furthermore, to input characters by using a keyboard becomes very bothersome work for disabled people even in a tabletop information equipment equipped with an ordinary keyboard, as well as the above-mentioned portable terminal apparatus.
On the other hand, there is a game machine or the like in which characters can be input by using a pointing device such as a cross-pad, a trackball or a joystick, and a selection button. According to this method for inputting characters, hiragana characters are specified one by one, using the cross-pad and the selection button, for example, on a table in which all the hiragana characters are disposed in a predetermined arrangement, and a character name in a game, simple instruction sentences are input.
Accordingly, the method for inputting characters used in such a game machine is not intended for writing ordinary papers, E-mail, etc., and to write papers by using this method for inputting characters is very inefficient and impractical.
The present invention solves the above-mentioned conventional problems, and its objective is to provide a character input apparatus and a recording medium in which a character input program is stored, which enable characters to be input at a high speed only by a pointing operation on a display screen, whereby characters can be input without using a keyboard and even when kanji characters in a phrase which is desired to be input are unknown.
A character input apparatus of the present invention includes: a character string dictionary which stores a number of character strings, consisting of at least one character and having a predetermined meaning, in a predetermined storage order; and an operation input unit which generates various instructing signals in accordance with an operation of an operator, the apparatus selecting a character string from the character string dictionary based on the instructing signal and inputting the character string, the apparatus comprising: display means having a display screen for displaying the selected character string and listing candidate character strings from which the character string is selected; a candidate character string extracting portion including selection means for selecting a predetermined character string from a plurality of the listed candidate character strings, based on a selection instructing signal generated by an operation in the operation input unit, and extraction threshold value changing means for continuously changing an extraction threshold value of character strings, based on a threshold value change instructing signal generated by an operation in the operation input unit, the candidate character string extracting portion extracting character strings from all the character strings stored in the character string dictionary as the candidate character strings, based on a large and small relationship between extraction priorities of the character strings and the extraction threshold value; and display control means for controlling the display means in such a manner that the candidate character strings extracted from the candidate character string extracting portion are listed and the character string selected by the selecting means is displayed on the display screen, wherein the operation input unit has a position specifying member for specifying a position on the display screen, and is designed in such a manner that the threshold value changing signal is generated by an operation of the position specifying member, and the display control means controls the display means in such a manner that, in regions on both sides of the position specified by the position specifying member on the display screen, the listed candidate character strings are shifted in an opposite direction to each other with respect to the specified position, when the number of the candidate character strings is increased or decreased in accordance with a change in the extraction threshold value.
In one embodiment, the character string dictionary, the candidate character string extracting portion, the display means, and the display control means are provided in an information equipment body for displaying and processing communication information, the operation input unit is provided in a remote control device separated from the information equipment body, for remotely controlling the information equipment body, a position specifying signal generated by an operation of the position specifying member in the operation input unit and the selection instructing signal generated by an operation in the operation input unit are transmitted from a transmitting portion of the remote control device to the information equipment body, a position is specified on the display screen of the display means provided in the information equipment body, based on the transmitted position specifying signal, and the candidate character strings are selected by the selecting means, based on the transmitted selection specifying signal.
In one embodiment, the display means includes, on the display screen, a selection character string display region for displaying the selected character string and a candidate character string display region for listing a predetermined number of candidate character strings from which the character string is selected, the selecting means selects a predetermined character string from a plurality of the candidate character strings listed in the candidate character string display region, based on the selection instructing signal generated by an operation in the operation input unit, the display control means controls the display means in such a manner that the candidate character strings extracted from the candidate character string extracting portion are listed in the candidate character string display region on the display screen and the character string selected by the selecting means is displayed in the selection character string display region on the display screen, the position specifying member in the operation input unit specifies a position on a two-dimensional coordinate corresponding to the candidate character string display region on the display screen, and the display control means controls the display means in such a manner that, in the candidate character string display region on the display screen, the listed candidate character strings are shifted so as to spread to upper and lower sides with respect to the position specified by the position specifying member, when the number of the candidate character strings is increased with a decrease in the extraction threshold value, and in the candidate character string display region on the display screen, the listed candidate character strings are shifted from both sides of the position specified by the position specifying member to the specified position, when the number of candidate character strings is decreased with an increase in the extraction threshold value.
In one embodiment, the candidate character string extracting portion compares an extraction priority of each character string in the character string dictionary with the extraction threshold value, and repeats first processing of extracting character strings whose extraction priorities are larger than the extraction threshold value from the character string dictionary and second processing of changing the extraction threshold value based on the threshold value change instructing signal generated by an operation in the operation input unit.
In one embodiment, the selecting means selects a predetermined candidate character string from a plurality of candidate character strings listed on the display screen whose extraction priorities are larger than the set extraction threshold value, based on the selection instructing signal generated by an operation in the operation input unit.
In one embodiment, the character string dictionary stores each character string, at least together with an extraction priority based on an appearance frequency thereof, and part of speech information based on the grammar of a language of the character strings to be input, a grammar dictionary is provided, which stores grammar information including a conjunction relationship between character strings disposed adjacent to each other, determined by the part of speech of the character strings in language of the character strings to be input, and the candidate character string extracting portion reads the part of speech information from the character string dictionary, regarding a latest character string among the character strings selected by the selecting means, and extracts character strings, which may come next to the latest selected character string and have extraction priorities larger than the extraction threshold value, as candidate character strings from the character string dictionary, based on the read part of speech information and the grammar information stored in the grammar dictionary.
In one embodiment, the candidate character string extracting portion includes appearance frequency updating means for updating an appearance frequency of each character string in the character string dictionary, based on a selection determining signal from the selecting means, and preferentially extracts character strings having large appearance frequencies as candidate character strings from the character string dictionary, considering that larger appearance frequencies correspond to higher extraction priorities.
In one embodiment, the character string dictionary and the candidate character string extracting portion are provided in a tabletop character input apparatus body, the operation input unit, the display means, and the display control means are provided in a portable terminal portion separated from the character input apparatus body, and the character input apparatus body and the portable terminal portion respectively have a transmitting/receiving portion for transmitting and receiving data through a wired channel or a radio channel, an operation signal generated by an operation of the position specifying member of the operation input portion in the portable terminal portion is transmitted to the candidate character string extracting portion in the character input apparatus body through the wired channel or the radio channel as data representing the specified position on the display screen of the display means in the portable terminal portion, the selection instructing signal generated by an operation in the operation input unit is transmitted to the selecting means in the character input apparatus body through the wired channel or the radio channel, extraction candidate character string data regarding the candidate character strings extracted by the candidate character string extracting portion is transmitted to the display control means in the portable terminal portion through the wired channel or the radio channel, and selection character string data regarding the character string selected by the selecting means is transmitted to the display control means in the portable terminal portion through the wired channel or the radio channel.
In one embodiment, the character string dictionary includes dictionary information as a language dictionary which stores information of a meaning of each character string, as well as each of the character strings, the operation input unit generates a meaning display instructing signal with respect to any character string displayed on the display screen by a predetermined operation, the display means forms a window for displaying a meaning on the display screen, based on the meaning display instructing signal from the operation input unit, and the display control means displays information of a meaning of a corresponding character string in the window for displaying a meaning formed on the display screen, based on the meaning display instructing signal.
In one embodiment, a language of the character strings to be input is Japanese or Chinese, a plurality of character strings are stored in an order based on a pronunciation thereof in the character string dictionary, and homonymous character strings are stored in an order based on the number of strokes (in a Chinese character) of a first character included in each of the character strings.
Furthermore, a recording medium of the present invention stores a program for implementing the above-mentioned character input apparatus of the present invention in a computer.
Hereinafter, the function of the present invention will be described.
According to the present invention, the candidate character string extracting portion, which extracts character strings from all the character strings stored in the character string dictionary as the candidate character strings, based on a large and small relationship between extraction priorities of the character strings and the extraction threshold value, includes extraction threshold value changing means for continuously changing an extraction threshold value of character strings, based on a threshold value change instructing signal generated by an operation in the operation input unit. Therefore, the number of candidate character strings to be extracted from the character string dictionary can be continuously changed by an operation in the operation input unit.
Furthermore, the display control means, which lists extracted candidate character strings on the display screen of the display means, controls the display means in such a manner that, in regions on both sides of the position specified by the position specifying member of the operation input unit on the display screen, the listed candidate character strings are shifted in an opposite direction to each other with respect to the specified position, when the number of the candidate character strings is increased or decreased in accordance with a change in the extraction threshold value. Therefore, the intended candidate character string can be rapidly displayed on the display screen.
Thus, candidate character strings listed at the initial time are shifted on the display screen, and a content of listed candidate character strings is continuously changed until the intended candidate character string appears on the display screen, by an operation such as changing a coordinate of a specified position on a two-dimensional display screen, using a mouse, a tablet, or the like as the operation input member. Therefore, a word, a clause, or a sentence can be successively input as a character string by selecting an appropriate character string from a list of candidate character strings which dynamically change by a selection operation of the operation input unit. In this case, unlike input of characters by using a keyboard, there is no dependence on language in an input operation, and a sentence can be correctly input, even in the case where spellings of Chinese characters in Japanese, English, etc. are not known.
In one embodiment, the character string dictionary, the candidate character string extracting portion, the display means, and the display control means are provided in an information equipment body for displaying and processing communication information, and the operation input unit is provided in a remote control device separated from the information equipment body, for remotely controlling the information equipment body. Therefore, when a position specifying operation and a selection operation in the operation input unit are conducted on the remote control device side, a position specifying signal and a selection instructing signal generated thereby are transmitted to the information equipment body side, so that extraction and selection of candidate character strings can be performed by a remote operation.
In one embodiment, a selection character string display region for displaying the selected character string and a candidate character string display region for listing a predetermined number of candidate character strings from which the character string is selected are set on the display screen of the display means. Therefore, candidate character strings and a selected character string are displayed in predetermined regions on the display screen, and it becomes easy to distinguish the candidate character strings from the selected character string on the display screen.
In one embodiment, the candidate character string extracting portion compares an extraction priority of each character string in the character string dictionary with the extraction threshold value, and repeats first processing of extracting character strings whose extraction priorities are larger than the extraction threshold value from the character string dictionary and second processing of changing the extraction threshold value based on the threshold value change instructing signal generated by an operation in the operation input unit. Therefore, in the case where there is no intended candidate character string in candidate character strings listed on the display screen, a content of candidate character strings to be listed is continuously changed by an operation in the operation input unit in accordance with extraction priorities, whereby the intended character string can be obtained as a candidate character string on the display screen. Thus, the intended character string can be searched efficiently and rapidly.
In one embodiment, the selecting means selects a predetermined candidate character string from a plurality of candidate character strings listed on the display screen whose extraction priorities are larger than the set extraction threshold value, based on the selection instructing signal generated by an operation in the operation input unit. Therefore, when the intended character string is displayed as a candidate character string on the display screen, this character string can be selected by the operation input unit. Thus, a required sentence can be input by placing the selected character string after the previously selected character string by an operation of the operation input unit.
In one embodiment, the character string dictionary stores each character string, together with an extraction priority thereof and part of speech information thereof, a grammar dictionary is provided, which stores grammar information including a conjunction relationship between character strings disposed adjacent to each other, determined by part of speech of the character strings, and the candidate character string extracting portion extracts character strings, which may come next to the latest selected character string, as candidate character strings, based on the part of speech information read from the character string dictionary and the grammar information stored in the grammar dictionary. Therefore, a list of candidate character strings to be displayed next on the display screen is determined based on grammar knowledge in the process of a sentence input operation. For example, in the case where the latest selected character string refers to the attributive form of a word with declined or conjugated endings, the substantives are preferentially displayed as candidate character strings, so that the intended character strings can be searched at a high speed.
In one embodiment, the candidate character string extracting portion includes appearance frequency updating means for updating an appearance frequency of each character string in the character string dictionary, based on a selection determining signal from the selecting means, and preferentially extracts character strings having large appearance frequencies as candidate character strings from the character string dictionary, considering that larger appearance frequencies correspond to higher extraction priorities. Therefore, a list of candidate character strings listed on the display screen can have a high hit rate (i.e., a high possibility of containing the intended character string), and the intended character string can be searched at a high speed.
In one embodiment, the character string dictionary and the candidate character string extracting portion are provided in a tabletop character input apparatus body, and the operation input unit, the display means and the display control means are provided in a portable terminal portion separated from the character input apparatus body. Therefore, the tabletop apparatus body having high processing ability will have a burdensome processing function of extracting a list of caudate character strings from the character string dictionary. For example, in the case where the portable terminal portion which performs input does not have sufficient processing ability, a display function is separated from a processing function by using data communication through a wired channel or a radio channel, whereby transportability of the portable terminal portion provided with the operation input portion and the display means can be prevented from being impaired.
In one embodiment, the character string dictionary includes dictionary information as a language dictionary which stores information on a meaning of each character string, as well as each of the character strings, the display means forms a window for displaying a meaning on the display screen, based on the meaning display instructing signal from the operation input unit, and the display control means displays information of a meaning of a corresponding character string in the window for displaying a meaning formed on the display screen, based on the meaning display instructing signal. Therefore, a meaning of a selected character string or meanings of listed candidate character strings from which a character string is selected can be confirmed in the process of a sentence input operation.
In one embodiment, a language of character strings to be input is Japanese or Chinese, a plurality of character strings are stored in an order based on a pronunciation thereof in the character string dictionary, and homonymous character strings are stored in an order based on the number of strokes (in a Chinese character) of a first character included in each of the character strings. Therefore, for example, in the case where the number of homonymous character strings displayed as candidate character strings on the display screen is larger than the number which can be displayed on the display screen, candidate character strings are displayed on the display screen by being arranged in the up and down direction and in the right and left direction based on the number of strokes of a first character in order of decreasing appearance frequency. Thus, even in the case where the number of homonymous character strings is larger than the number which can be displayed, a user can search the intended character string, based on the second ordering element such as the number of strokes as well as Japanese phonetic characters.